add wipe prevention via file in data root dir (#548)

* if a file named root_manifest.ignore_schema_mismatch exists in the root data dir, ignore schema mismatch

2 files changed, 21 insertions, 3 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ef6d2aa4c..66e7d1d07 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,7 @@
 ##
+- Feature: Adding a file named `root_manifest.ignore_schema_mismatch` in the root of zenserver data dir prevents wipe of data when schema mismatches
+
+## 0.2.34
 - Bumped zenserver data schema (to '5') to wipe corrupted state caused by version 0.2.31/0.2.32
 - Bugfix: Fix hang on ZenServerInstance shutdown on Mac/Linux
 - Improvement: Event implementation now uses `std::atomic_bool` instead of `volatile bool` for correctness
diff --git a/src/zenserver/zenserver.cpp b/src/zenserver/zenserver.cpp
index b87679b7d..8359f5088 100644
--- a/src/zenserver/zenserver.cpp
+++ b/src/zenserver/zenserver.cpp
@@ -363,9 +363,24 @@ ZenServer::InitializeState(const ZenServerOptions& ServerOptions)
 
 				if (ManifestVersion != ZEN_CFG_SCHEMA_VERSION)
 				{
-					WipeState = true;
-					WipeReason =
-						fmt::format("Manifest schema version: {}, differs from required: {}", ManifestVersion, ZEN_CFG_SCHEMA_VERSION);
+					std::filesystem::path ManifestSkipSchemaChangePath = m_DataRoot / "root_manifest.ignore_schema_mismatch";
+					if (ManifestVersion != 0 && std::filesystem::is_regular_file(ManifestSkipSchemaChangePath))
+					{
+						ZEN_INFO(
+							"Schema version {} found in '{}' does not match {}, ignoring mismatch due to existance of '{}' and updating "
+							"schema version",
+							ManifestVersion,
+							ManifestPath,
+							ZEN_CFG_SCHEMA_VERSION,
+							ManifestSkipSchemaChangePath);
+						UpdateManifest = true;
+					}
+					else
+					{
+						WipeState = true;
+						WipeReason =
+							fmt::format("Manifest schema version: {}, differs from required: {}", ManifestVersion, ZEN_CFG_SCHEMA_VERSION);
+					}
 				}
 			}
 		}